Available model-based development tools can show un-reachability of certain model elements. Some tools can generate test inputs that satisfy standard coverage objectives as well as user-defined test objectives and requirements. These test inputs can also be combined with tests defined using measured data so that simulations are testing against model coverage, requirements, and real-world scenarios.
However, some important coverage criteria (e.g., mask modified condition/decision coverage (MC/DC)) are not supported by available model-based development tools and redundant test cases are generated to satisfy certain coverage criteria. Further, some conventional development tools do not provide the capability of augmenting test cases to satisfy coverage criteria.
Software certification standards (e.g., DO-178C) require safety-critical software, such as aviation software, to be tested with strict test coverage (including MC/DC). These standards can require that each condition that could independently affect the decision be tested. Manual inspection of the model/code to identify the inputs sequences that drive an internal variable to a particular value is hard and time-consuming, especially when the aviation software system is large and complex.